Purpose: This study aims to empirically validate an innovative work behaviour-enhancing model of employability in small- and medium-sized enterprises (SMEs), and to examine possible moderating effects of age. Design/methodology/approach: Data have been collected from 487 pairs of employees and their immediate supervisors who worked in 151 SMEs. Structural equation modelling (SEM) has been used to investigate the predictive validity of employability on innovative work behaviour using a multi-source approach. The moderating effect of employee age on the relationship between, on the one hand, self-ratings and supervisor ratings of employability, and, on the other hand, innovative work behaviour has been tested using multi-group SEM. Findings: Results suggest that self-rated employability correlates positively with supervisor-rated innovative work behaviour, and that supervisor-rated employability correlates positively with self-rated innovative work behaviour. Age appeared to have a weak influence on the relationship between employability and innovative work behaviour; more specifically, in case of a higher age, the relationship was stronger., Research limitations/implications: The cross-sectional design is a limitation of this study. Another limitation relates to the generalizability of the study findings outside the context in which the research has been undertaken. The relational meaning of employee age might be different in other cultures. Practical implications: Supervisors appear to play an essential role in providing an age-friendly working life for employees. Moreover, as SMEs often do not employ professionals to manage human resources, supervisors themselves have to carry the responsibility to encourage aging employees to develop themselves the enhancing innovative work behaviour. Originality/value: This study is the first to investigate the predictive validity of employability on innovative work behaviour and the effects of age on this relationship.